From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6835DC433FE for ; Mon, 27 Sep 2021 07:23:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 48ECA6023D for ; Mon, 27 Sep 2021 07:23:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233253AbhI0HZW (ORCPT ); Mon, 27 Sep 2021 03:25:22 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:34930 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233158AbhI0HZQ (ORCPT ); Mon, 27 Sep 2021 03:25:16 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 18R4fxfu010455; Mon, 27 Sep 2021 03:22:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=CjOlcnT7iJv79IU4P9/oIQ5aIU66wolcKEh57i1aef0=; b=R9Zo6rOi5sEtPF/jz79SMF+QOw8ZsBwnEkicDXMKstc+js70xMLJ5i+agBbUekhLEqLR Riq52GuXS7BkoIeatHGqjMJqg6X+sq9GMbrECM5MmPAudfQzUfMLZXqA4WIYz2prPMQi NRGyhPAyQzpNenbkr3M8+DmiUtn43GFhQo9zhTdQTTw5exh9yWGEFAmNLDaUbtLpHAGO n7KDW8mljRv3Ky4xZfNkkQl1vlezSvjZZfVvB6t91dxhd2ElVmfb9DDcZWzPHA/W2hHr Hx+lJOpkpOeJ/VQZISfyjwGRA6TkmASGsdGqJV35YVE7h94QvR6r3uDbww4sDPKbhTIn kA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bagvqcsrd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 27 Sep 2021 03:22:59 -0400 Received: from m0098404.ppops.net (m0098404.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 18R5o8Ah007641; Mon, 27 Sep 2021 03:22:58 -0400 Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bagvqcsqb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 27 Sep 2021 03:22:58 -0400 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 18R7H9Q4001359; Mon, 27 Sep 2021 07:22:55 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma05fra.de.ibm.com with ESMTP id 3b9ud8rx63-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 27 Sep 2021 07:22:55 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 18R7Mp6J42467650 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 27 Sep 2021 07:22:51 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4D3E95204F; Mon, 27 Sep 2021 07:22:51 +0000 (GMT) Received: from li-43c5434c-23b8-11b2-a85c-c4958fb47a68.ibm.com (unknown [9.171.4.236]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id ABAD052051; Mon, 27 Sep 2021 07:22:49 +0000 (GMT) Subject: disabling halt polling broken? (was Re: [PATCH 00/14] KVM: Halt-polling fixes, cleanups and a new stat) To: Sean Christopherson , Paolo Bonzini , David Matlack , Jon Cargille , Jim Mattson Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-kernel@vger.kernel.org, Jing Zhang , Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Janosch Frank References: <20210925005528.1145584-1-seanjc@google.com> From: Christian Borntraeger Message-ID: <03f2f5ab-e809-2ba5-bd98-3393c3b843d2@de.ibm.com> Date: Mon, 27 Sep 2021 09:22:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210925005528.1145584-1-seanjc@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: YhudcLNxmoRTm9--b5hlc8B3xu2hjRt_ X-Proofpoint-GUID: AXC2xKJr4IU02TPnWWKjhfFDtMWQ5xNx X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-09-27_01,2021-09-24_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 priorityscore=1501 mlxscore=0 phishscore=0 mlxlogscore=974 lowpriorityscore=0 impostorscore=0 adultscore=0 clxscore=1015 suspectscore=0 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2109270046 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org While looking into this series, I realized that Davids patch commit acd05785e48c01edb2c4f4d014d28478b5f19fb5 Author: David Matlack AuthorDate: Fri Apr 17 15:14:46 2020 -0700 Commit: Paolo Bonzini CommitDate: Fri Apr 24 12:53:17 2020 -0400 kvm: add capability for halt polling broke the possibility for an admin to disable halt polling for already running KVM guests. In past times doing echo 0 > /sys/module/kvm/parameters/halt_poll_ns stopped polling system wide. Now all KVM guests will use the halt_poll_ns value that was active during startup - even those that do not use KVM_CAP_HALT_POLL. I guess this was not intended?